You and a Friend Are Student Assistants in a Research

You and a friend are student assistants in a research laboratory that investigates the anti-cancer properties of proteins isolated from marine organisms.Your friend mentions that she is using a BAC vector to insert shark DNA into Escherichia coli,but after repeated attempts,has found that the bacterial cells fail to synthesize the encoded protein.What is your advice?

A) If the shark DNA is unmodified,it contains introns that are not recognized by bacteria,therefore protein synthesis will not occur.
B) Since shark DNA is eukaryotic,the cloning vector should be a YAC derived from yeast rather than a BAC derived from bacteria.
C) It is impossible to clone eukaryotic DNA into a bacterial host,since eukaryotic DNA has introns and prokaryotic DNA does not.
D) Because Escherichia coli is not naturally competent,it cannot serve as the cloning host for foreign DNA.